What Are Friends For? A Longer Life

Stuart Bradford

In the quest for better health, many people turn to doctors, self-help books or herbal supplements. But they overlook a powerful weapon that could help them fight illness and depression, speed recovery, slow aging and prolong life: their friends.

Podcast: Science TimesResearchers are only now starting to pay attention to the importance of friendship and social networks in overall health. A 10-year Australian study found that older people with a large circle of friends were 22 percent less likely to die during the study period than those with fewer friends. A large 2007 study showed an increase of nearly 60 percent in the risk for obesity among people whose friends gained weight. And last year, Harvard researchers reported that strong social ties could promote brain health as we age.

“In general, the role of friendship in our lives isn’t terribly well appreciated,” said Rebecca G. Adams, a professor of sociology at the University of North Carolina, Greensboro. “There is just scads of stuff on families and marriage, but very little on friendship. It baffles me. Friendship has a bigger impact on our psychological well-being than family relationships.”

In a new book, “The Girls From Ames: A Story of Women and a 40-Year Friendship” (Gotham), Jeffrey Zaslow tells the story of 11 childhood friends who scattered from Iowa to eight different states. Despite the distance, their friendships endured through college and marriage, divorce and other crises, including the death of one of the women in her 20s.

Using scrapbooks, photo albums and the women’s own memories, Mr. Zaslow chronicles how their close friendships have shaped their lives and continue to sustain them. The role of friendship in their health and well-being is evident in almost every chapter.

Two of the friends have recently learned they have breast cancer. Kelly Zwagerman, now a high school teacher who lives in Northfield, Minn., said that when she got her diagnosis in September 2007, her doctor told her to surround herself with loved ones. Instead, she reached out to her childhood friends, even though they lived far away.

“The first people I told were the women from Ames,” she said in an interview. “I e-mailed them. I immediately had e-mails and phone calls and messages of support. It was instant that the love poured in from all of them.”

When she complained that her treatment led to painful sores in her throat, an Ames girl sent a smoothie maker and recipes. Another, who had lost a daughter to leukemia, sent Ms. Zwagerman a hand-knitted hat, knowing her head would be cold without hair; still another sent pajamas made of special fabric to help cope with night sweats.

Ms. Zwagerman said she was often more comfortable discussing her illness with her girlfriends than with her doctor. “We go so far back that these women will talk about anything,” she said.

Ms. Zwagerman says her friends from Ames have been an essential factor in her treatment and recovery, and research bears her out. In 2006, a study of nearly 3,000 nurses with breast cancer found that women without close friends were four times as likely to die from the disease as women with 10 or more friends. And notably, proximity and the amount of contact with a friend wasn’t associated with survival. Just having friends was protective.

Bella DePaulo, a visiting psychology professor at the University of California, Santa Barbara, whose work focuses on single people and friendships, notes that in many studies, friendship has an even greater effect on health than a spouse or family member. In the study of nurses with breast cancer, having a spouse wasn’t associated with survival.

While many friendship studies focus on the intense relationships of women, some research shows that men can benefit, too. In a six-year study of 736 middle-age Swedish men, attachment to a single person didn’t appear to affect the risk of heart attack and fatal coronary heart disease, but having friendships did. Only smoking was as important a risk factor as lack of social support.

Exactly why friendship has such a big effect isn’t entirely clear. While friends can run errands and pick up medicine for a sick person, the benefits go well beyond physical assistance; indeed, proximity does not seem to be a factor.

It may be that people with strong social ties also have better access to health services and care. Beyond that, however, friendship clearly has a profound psychological effect. People with strong friendships are less likely than others to get colds, perhaps because they have lower stress levels.

Last year, researchers studied 34 students at the University of Virginia, taking them to the base of a steep hill and fitting them with a weighted backpack. They were then asked to estimate the steepness of the hill. Some participants stood next to friends during the exercise, while others were alone.

The students who stood with friends gave lower estimates of the steepness of the hill. And the longer the friends had known each other, the less steep the hill appeared.

“People with stronger friendship networks feel like there is someone they can turn to,” said Karen A. Roberto, director of the center for gerontology at Virginia Tech. “Friendship is an undervalued resource.